Denton Finds Rare Mosquito-Transmitted Virus

North Texans have heard a lot about West Nile virus and Zika virus over the past few years, but now another mosquito-carried illness is joining the list in Denton.

On Friday, the City of Denton announced a mosquito trapped off of West University Drive and Gay Street, near the Rayzor Ranch shopping area, tested positive for California Serogroup virus.

City Environmental Services Director Dr. Ken Banks said the illness, and even the mosquitoes that carries, it is extremely rare in Texas.

Of all of Denton’s trapped mosquitoes, Banks said about 0.3 percent are the flood water mosquito needed to bring the virus around, and statewide could only find about five instances of the illness showing up in mosquitoes since 2009.

Most commonly found in the upper Midwest and mid-Atlantic states, California Serogroup is, as the name suggests, a grouping of viruses that are each very different.

Dr. Banks said most that would show up in this rare case are illnesses that show up in wildlife and aren’t an issue for humans.

Others though, especially one called La Crosse Encephalitis, are a concern.

According to the Centers for Disease Control and Prevention, La Crosse virus is a lot like the West Nile virus in that there is a lesser form that carries a lot of flu symptoms and a more serious neuroinvasive disease form that can lead to long term complications, and in very rare situations, death.

Banks said the likelihood of that being in North Texas is very low and that it’s very unlikely this situation is of a serious health risk to the area, but until they know for sure which of the Serogroup their mosquito carried, they are proceeding with caution.

"We're waiting for an actual virus identification,” said Banks. β€œIt could come back that it's a wildlife virus, it very likely will. There is a possibility, though, that it could be something like La Crosse, and if that's the case, we're going to have to look into this a little further."

In the meantime, the city has elected to keep their mosquito alert level where it is, but crews are monitoring more aggressively in the area where that sample was trapped earlier this month.

Banks said, regardless of which form of the virus the CDC finds in that sample, the defense against getting it is the same as they recommend with the West Nile virus: use bug spray with deet, avoid the outdoors at dusk and dawn, drain standing water and dress in long sleeves and long pants.

City leaders are awaiting the results of that test and plan to put out more information when they know exactly what they found.

Contact Us